Acquisitions, Goodwill, and Acquired Intangible Assets Expected Future Amortization Expense of Acquired Intangible Assets (Detail) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Business Combinations [Abstract]
2016		$ 218
2017		191
2018		131
2019		103
2020		41
Thereafter		78
Acquired Intangibles, Net	[1]	$ 762	$ 764

[1] Intangible assets have estimated useful lives of between one and ten years.